1. Field of the Invention
This invention relates to automatic control systems, and more particularly to monitoring and control of circuits governed by circuit breakers.
2. Description of the Related Art
The following descriptions and examples are not admitted to be prior art by virtue of their inclusion within this section.
Electrical wiring in houses and other-buildings typically includes multiple circuits, each governed by a circuit breaker. One or more electrical devices, such as appliances, lamps, or tools, may be connected along each circuit. If an excessive amount of current flows through a given circuit, the corresponding circuit breaker is designed to xe2x80x9ctripxe2x80x9d, or open the circuit. In this way, devices connected along the affected circuit may be protected from damage caused by the excess current, while power may be maintained to devices on other circuits. Conventionally, the breaker is manually reset to restore power to the circuit once the condition causing the breaker to trip has been corrected.
If a circuit breaker trips at a time when the building housing the circuit is unoccupied, however, resetting of the circuit breaker is generally delayed. This may be problematic in situations for which removal of power to a device on the circuit causes damage. For example, loss of power to a refrigerator or freezer may cause the stored food to become spoiled. In situations for which ambient temperatures are extremely hot or cold, loss of power to an air conditioning or heating unit may result in extreme discomfort or even danger to, for example, animals within a house. It would therefore be desirable to decrease the delay in resetting a circuit breaker that becomes tripped when manual intervention is not immediately available. Furthermore, even when a person is available to reset a tripped circuit breaker, the process can be tedious and time-consuming. Depending upon how many devices along the circuit were drawing power just prior to the tripping of the breaker, it may take some time to determine which device or devices caused the breaker to trip. Accordingly, it would also be desirable to improve the speed and accuracy of determining which devices along a circuit should be restarted after a circuit breaker trips.
The problems outlined above are in large part addressed by a system, method and program in which circuit profile information characterizing a circuit governed by a circuit breaker is used to determine a reset strategy for resetting of the circuit breaker. The circuit profile information may include an identification of any devices connected along the circuit, where the devices may include various electrical units such as appliances, light fixtures, or tools. The circuit profile information may further include device profile information corresponding to such devices. The device profile information may include, for example, a history of the current and/or power drawn by the device prior to the tripping of the circuit breaker. Other information included in the device profile information may be, for example, instructions as to whether the device should be restarted if possible after a circuit breaker is tripped, or instructions for how much time should elapse between attempts to restart the device. The circuit profile information could also include a history of previous trippings of the circuit breaker, and status and/or history information regarding any ground fault interrupters which may be connected along the circuit.
The reset strategy for resetting of the circuit breaker is a sequence of one or more events leading to the resetting of the tripped breaker. Such events may include, for example, switching of devices on or off, and/or resetting of the breaker. In an embodiment of the method, the resetting is done automatically if possible. If it is determined from the circuit profile information that automatic resetting of the breaker is unsafe or otherwise undesirable, the reset strategy may include sending an alert message soliciting manual intervention to reset the breaker. In an embodiment of the method, one or more commands are sent to implement the reset strategy. For example, an embodiment of a method for controlling a circuit governed by a circuit breaker includes detecting that the circuit breaker has tripped, receiving device profile information from a device connected along the circuit, using the device profile information to formulate a reset strategy for the circuit breaker, and sending a command as part of implementing the reset strategy. The method may further include sending a query to the device before receiving the device profile information.
An embodiment of a system described herein for controlling a circuit having a circuit breaker includes a system controller operably coupled to the circuit and the circuit breaker, where the system controller is adapted to use circuit profile information to determine a reset strategy. The circuit profile information may include device profile information, and the system controller may include a processor, a transmitter adapted to send a query to a device connected along the circuit, a receiver adapted to receive device profile information from the device, and a storage medium adapted to store the device profile information. In further embodiments, the system may further include a device controller coupled to the circuit and to the device, where- the device controller is adapted to receive a query or command from the system controller. The device controller may include a processor, a receiver adapted to receive the query or command, a transmitter adapted to send device profile information, and a storage medium adapted to store the device profile information.
In addition to the method and system described above, a computer-usable carrier medium is contemplated herein. The carrier medium may be a storage medium, such as a magnetic or optical disk, a magnetic tape, or a memory. In addition, the carrier medium may be a transmission medium, such as a wire, cable, or wireless medium along which data or program instructions are transmitted, or a signal carrying the data or program instructions along such a wire, cable or wireless medium. The carrier medium may contain program instructions executable for carrying out embodiments of the methods described herein, and/or data such as the circuit profile information and device profile information described above.